1.5.1 shows "Error while running external preprocessor" error message on top of every reason file.

When I update the reason-vscode to 1.5.1, I can see messages like below in every `.re` file:

```
The filename, directory name, or volume label syntax is incorrect.
File "", line 1:
Error: Error while running external preprocessor
Command line: "D:\projects\space-client\node_modules\bs-platform\lib\reactjs_jsx_ppx_2.exe" "C:\Users\faith\AppData\Local\Temp\camlppx094ca7" "C:\Users\faith\AppData\Local\Temp\camlppxb1f0e4"
```

When I downgraded it to 1.4.1, there was no problem.

Reproduce the error in a .re file with reason-vscode 1.5.1 on Windows, then compare the same file with version 1.4.1. Start by tracing the displayed external preprocessor command, including reactjs_jsx_ppx_2.exe and its temporary-file arguments; done means preprocessing succeeds without the error message.

Written by the indexing model from the issue text.